1) General canopy characteristics

The Ofenpass Mountain Pine forest inventory was carried out over a large area from which a 100×100 m² subplot was selected for RAMI. The origin of the coordinate system was placed at the south-western end of this area. However, in order to include the tree crowns of those trees that were located within the 1 hectare area of the RAMI Mountain Pine Winter stand representation it was necessary to expand the scene area slightly beyond the one hectare. Maintaining the origin of the tree location coordinate system thus resulted in some negative x,y values in the table below. Overall architectural characteristics of the scene are thus as follows:

2) Foliage structure

The table below provides the architectural characteristics of the shoots of the trees used in the Ofenpass Pine stand representation. Individual shoots are generated by stacking four sub-shoots - with architectures based on the geometry proposed by Smolander et al., 2003 (RSE) - on top of each other. RT models capable of representing the architecture of individual foliage elements with a series of geometric primitives (triangle, sphere, cylinder) may want to use the information provided in the ASCII (text) files accessible from the last row in each table below.

Mountain pine shoot number of needles 240 total needle area* 224.614 cm² needle lengtho 2.8 and 4.5 cm needle diameter 0.05 cm angle between twig and needleo 30° and 40° fascicle angle 0 - 27.7° twig length 9.0 cm twig diameter 0.5 cm structural description file (geometric primitives) click here * This total needle area value arises if the needles are represented as elongated spheres (as is the case in the ASCII file accessible via the link in the last row of the above table). If individual needles are represented as cylinders (with discs as endcaps) then the total needle area of the shoot is different and the number of shoots per mountain pine tree should be adjusted accordingly. o For a detailed description of the shoot structure please read the header of the structural description file accessible via the link in the last row of this table.

3) Tree structure

The Ofenpass Mountain Pine forest is generated on the basis of 13 individual tree representations. Twelve of these pertain to live Mountain pine (Pinus Montana) trees and one refers to a dead Mountain pine tree representation. The latter is due to the fact that about 20% of the overall tree density is made up of dead (standing) trees. The table below provides an overview of some structural characteristics of these various tree representations. For those RT models capable of representing the 3D architecture of a given trees in a voxelised manner, or alternatively, through a series of geometric primitives the last four lines of this table contain links to data files with detailed specifications of the foliage and wood structural properties of the Ofenpass Mountain Pine forest (Winter) trees.

tree identifier PIMO1 PIMO2 PIMO3 PIMO4 PIMO5 PIMO6 PIMO7 tree height [m] 3.24 5.99 6.51 8.84 9.08 11.01 10.61 diameter at breast height (DBH) [cm] 8.0 11.0 12.4 15.4 13.4 16.8 24.4 Foliage normal distribution: zenith angle= graph data graph data graph data graph data graph data graph data graph data Foliage normal distribution: azimuth angle= graph data graph data graph data graph data graph data graph data graph data height to live/green crown [m] 0.32 1.43 2.06 3.22 4.77 4.96 7.38 crown radiusx mean [m]: maximum [m]: picture 0.27 0.94 picture 0.23 1.02 picture 0.46 1.34 picture 0.42 1.15 picture 0.25 1.03 picture 0.57 1.70 picture 0.38 1.18 vertical profile of crown radii* [m] graph data graph data graph data graph data graph data graph data graph data half-total foliage area of tree# [m²] 17.0819 4.08798 23.1914 17.6322 4.5709 14.3978 5.42443 vertical profile of leaf area o [m²] graph data graph data graph data graph data graph data graph data graph data total wood area of tree [m²] 2.1175 2.53444 5.96951 5.84187 4.8390 9.93186 11.5582 vertical profile of wood areao [m²] graph data graph data graph data graph data graph data graph data graph data tree shape image foliage structure (triangle mesh) file file file file file file file wood structure (triangle mesh) file file file file file file file

tree identifier PIMO8 PIMO9 PIMO10 PIMO11 PIMO12 PIMO13 PIMO14 tree height [m] 13.60 13.07 12.39 14.65 15.12 10.02 1.09 diameter at breast height (DBH) [cm] 32.4 34.6 34.4 36.0 25.6 22.6 NA Foliage normal distribution: zenith angle= graph data graph data graph data graph data graph data NA graph data Foliage normal distribution: azimuth angle= graph data graph data graph data graph data graph data NA graph data height to live/green crown [m] 2.82 7.67 10.23 8.81 10.32 NA 0.12 crown radiusx mean [m]: maximum [m]: picture 0.60 1.77 picture 0.33 1.18 picture 0.27 1.08 picture 0.54 1.70 picture 0.36 1.20 picture 0.14 0.77 picture 0.17 0.43 vertical profile of crown radii* [m] graph data graph data graph data graph data graph data NA graph data half-total foliage area of tree# [m²] 20.1254 6.7497 2.21245 15.7005 4.3575 0.0 5.89612 vertical profile of leaf area o [m²] graph data graph data graph data graph data graph data NA graph data total wood area of tree [m²] 20.0702 12.6872 11.3227 19.7395 12.9358 5.54147 0.32731 vertical profile of wood areao [m²] graph data graph data graph data graph data graph data graph data graph data tree shape image foliage structure (triangle mesh) file file file file file NA file wood structure (triangle mesh) file file file file file file file

= The zenith angle of the foliage normal is defined as the angle between the vertical and the normal of the main twig of the shoot (for a shoot axis aligned along the z-axis the normal was arbitrarily chosen to lie along the y-axis). Rather than spanning the full range of possible zenith angles (i.e., from 0 to 180 degree) as could be expected for non-flat asymmetric objects, it was chosen to follow the convention of foliage normals pointing only into the upper hemisphere. This is because RAMI participants, that make use of this foliage normal distribution information, will in all likelihood have models where scatterers are represented as flat (disc or equilateral triangle shaped) objects. However, should your model require a description of the foliage normal zenith angle distribution up to 180 degrees then please do not hesitate in contacting us and we will provide this information to you. For both the zenith and azimuth angle distributions the 'graph' link shows an image of the normalised foliage normal distribution versus zenith (or azimuth) angle of the foliage normal. The 'data' files for the zenith and azimuth angle distribution have three columns indicating 1) the upper value of the zenith (or azimuth) angle in a given bin, 2) the fraction of foliage area having a normal in this zenith (or azimuth) angle range, and 3) the fraction of wood area having a normal that falls in this zenith (or azimuth) angle range. Bin angle widths were chosen to be 5 degrees and 10 degrees for zenith and azimuth angles, respectively. x The crown radius of actual trees is varying with azimuth angle. This can be seen in the various pictures showing a perspective-free nadir view of a given tree located at x=0,y=0 (concentric circles indicate the distance from the origin in steps of 0.25m). The mean and maximum values were computed from the triangle objects making up the 3D trees depicted in the picture in the the fourth-last row of each table column. * The graphs show the maximum radial distance of foliage elements in a given height interval plotted against the upper height level of that height interval. The data files have five columns: lower-height-of-bin-in-units-of-meters     upper-height-of-bin-in-units-of-meters     minimum_radial-distance_of_foliage-in-units-of-m     maximum_radial-distance_of_foliage-in-units-of-m.     mean_radial-distance_of_foliage-in-units-of-m # This value corresponds to the one-sided leaf area for flat leaves. For Mountain pine trees it corresponds to the sum of the (maximum) silhouettes of all the individual needles in the tree (i.e., half the total needle area per tree). o The data files have 3 columns: lower-height-of-bin-in-units-of-meters     upper-height-of-bin-in-units-of-meters     area-of-wood-or-foliage-in-units-of-m2.

4) Stand structure

The Ofenpass Mountain Pine forest is composed of 991 individual trees. The following table indicates how these trees are distributed among the above tree classes and specifies their respective x,y locations of the tree centers of each tree class in the forest stand. The last row of this table contains an ASCII file with tree rotation and translation information for those RT models capable of ingesting the detailed 3D architecture of the tree models specified in the previous section.

The Figure below shows the tree locations for the Ofenpass Mountain pine (Winter) stand. Crown of live trees are open circles. Red dots are trees belonging to the (randomly dispersed) understorey. Black dots are (randomly dispersed) dead trees. The origin of the coordinate system is in the lower left hand side corner of the image.

RAMI participants with 3D RT models capable of representing objects using geometric primitives can download a single compressed ZIP archive with all the tree architectural ASCII information that is listed in the above tables by clicking HERE. Note: The size of the compressed archive is about 1.8 megabytes. It contains 42 ASCII files and can be unzipped using 'WINZIP' on windows or 'unzip' on linux/unix operating systems. Beware that the inflated archive will take up 9.7 Megabytes of storage.